How to Make Great Data Visualisations

Aurélien Goutsmedt

ICHEC Brussels Management School

UC Louvain, ISPOLE

Thomas Laloux

UC Louvain, ISPOLE

April 28, 2025

What makes a great data visualisation?

One thing’s for sure: it’s never a pie chart…

General Considerations

Healy (2018) Data Visualization: A Practical Introduction. Princeton University Press.

  • General discussion on commong issues regarding data visualizations
  • Applications to social sciences
  • Focus on R package ggplot2 (Wickham, 2016)

Why visualizing data?

  • Exploring your data (identifying patterns and problems, etc…)
    • Extract information intuitively, efficiently, and accurately

  • Discovering relationships in your data
  • Communicating information with precision, in a concise way
  • Displaying your main results
  • More sociological dimensions: bolster credibility
  • but, it is not sufficient to “look at data” for good analysis, and anyway, it comes with some risks

Edward Tufte’s main principle

Graphical excellence is the well-designed presentation of interesting data—a matter of substance, of statistics, and of design. … [It] consists of complex ideas communicated with clarity, precision, and efficiency. … [It] is that which gives to the viewer the greatest number of ideas in the shortest time with the least ink in the smallest space. … [It] is nearly always multivariate. … And graphical excellence requires telling the truth about the data. (Tufte, 1983, p. 53)

Other criteria

Three hurdles towards great data visualisation

Bad tastes

Bad data (use)

Perception issues: colors

Perception issues: shapes and scales

Practical considerations: playing with data

Slides ggplot2

Presenting dataset

ISPOLE data

References

Healy, K. (2018). Data visualization: A practical introduction. Princeton University Press.
Tufte, E. R. (1983). The Visual Display of Quantitative Information (1st edition). Graphics Press USA.
Wickham, H. (2016). ggplot2: Elegant graphics for data analysis. Springer-Verlag New York. https://ggplot2.tidyverse.org